Science activities for the busy teacher.
This blog will be participating in the A to Z challenge for April 2016. Posts are abbreviated for visitors. Pertinent links for more in-depth information are provided. Warning to non-teachers, comments will get very honest answers concerning anything unsafe to do in a classroom. Teachers would not take it personal. Neither should you. Safety is first.

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Monday, December 17, 2012

Static Electricity

This is an incredibly simple and fun activity.

Materials:
Roll of clingfilm or plastic wrap. In the United States, Reynolds brand tends to work the best.
Roll of paper towels
Small bits of paper (Empty the hole punch ;=] )
Equally small pieces of aluminum foil, rubber bands, salt, pencil shavings, plastic.

Part 1
Distribute a square or rectangle of plastic wrap and paper towel to each student.
Have students flatten the plastic wrap on their desktop.
Next, students rub the plastic wrap with the paper towel.
As they rub, ask them what they think the plastic wrap will do if they lift it by opposite corners. Invariably, they will say it will wad into a ball or similar answers.
After a minute or two, have students place the paper towel aside.

Instruct students to lift by opposite corners. Surprisingly, the wrap will open instead of collapsing. This is because they created a charge on the opposite side, thus creating the same and opposite charge on the bottom. Like charges repel.
They will want to do this again which I always allowed them to do so.

Part II
I pass out the items to test in a particular order with the salt being last. When they recharge their wrap and salt adheres to the wrap, the wrap tears.

Have students charge the wrap and hold it over the small pieces of paper. They will be attracted to the wrap.
Have students charge the wrap and hold it over various sizes of aluminum foil.
Have students charge the wrap and hold it over small bits of rubber and plastic.
Have students charge the wrap and hold over salt. Students enjoyed this the most. Salt is an ionic compound and is very attracted. I liked students to observe that as the charge lessened, the salt began to drop. Recharging the wrap and testing again is good.
Have students recharge the wrap and hold over pencil shavings.

You can choose more items to test. The more ionic a substance is, the greater the reaction. Covalent solids like rubber are not affected by the charge.

Safety Always

These activities are chosen and designed to be safe. The nature of an accident is it is not planned. Water is a very safe substance. Spill water on the floor, someone can slip and fall. The greatest safety rule is to Think before you Do.

I taught science for over 30 years. I had a few accidents in the classroom. Fortunately, no one was seriously hurt. Purchasing a set of safety glasses at the dollar store is a good investment. I know parents, schools, etc shouldn't ask you to buy such. Life is all too real. If someone got hurt, you would have immense guilt.

Know your audience. There is a balance between a math teacher too afraid to let a group of students use a compass because it has a sharp point and the free for all approach some teachers use.

I've got a safety contract that I used in the classroom. Feel free to use it. The shorter and clearer the rule, the more compliance you will get. If you have that child or parent that you have to think like a Philadelphia lawyer around, realize it is an opportunity to deliver your instruction more clearly and safely.

I will post any warnings or cautions that I can think when making the posts. However, I cannot be responsible for what happens in your classroom or home. Use any of these activities at your own risk.